scholarly journals The Trigeminal Nerve and Augmentation of Regional Cerebral Blood Flow during Experimental Bacterial Meningitis

1996 ◽  
Vol 16 (6) ◽  
pp. 1319-1324 ◽  
Author(s):  
Joerg R. Weber ◽  
Klemens Angstwurm ◽  
Geoffrey M. Bove ◽  
Wolf Bürger ◽  
Karl M. Einhäupl ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Bacterial Meningitis ◽  
Trigeminal Nerve ◽  
Regional Cerebral Blood Flow ◽  
Nerve Fibers ◽  
Regional Cerebral Blood ◽  
Doppler Flowmetry ◽  
Wall Components ◽  
Brain Water

We investigated whether trigeminal nerve fibers contribute to enhanced regional cerebral blood flow (rCBF) in a rat model of experimental bacterial meningitis. rCBF was measured continuously for 6 h by laser Doppler flowmetry through thinned bone over the frontal cortex. Meningitis was induced with pneumococcal cell wall components and confirmed by a significant increase of (a) leukocytes within the cerebrospinal fluid, (b) brain water content, (c) intracranial pressure and (d) rCBF. The increase of rCBF was significantly attenuated ( p < 0.05) at 3, 4, 5, and 6 h in animals after a chronic (200 ± 21% versus 138 ± 13% at 6 h on the intact and denervated sides, respectively) but not after an acute section of the nasociliary branch of the trigeminal nerve. We conclude that elevations in blood flow during the early phase of bacterial meningitis are mediated in part by the trigeminal nerve, probably by local perivascular release of neuropeptides from afferent axons innervating the meninges.

The Characteristics of Laser-Doppler Flowmetry for the Measurement of Regional Cerebral Blood Flow

Neurosurgery ◽  
1995 ◽  
Vol 36 (2) ◽  
pp. 358???364 ◽  
Author(s):  
Osamu Fukuda ◽  
Shunro Endo ◽  
Naoya Kuwayama ◽  
Jun Harada ◽  
Akira Takaku
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Laser Doppler Flowmetry ◽  
Regional Cerebral Blood Flow ◽  
Laser Doppler ◽  
Regional Cerebral Blood ◽  
Doppler Flowmetry

The Cyclooxygenase Inhibitors Indomethacin and Rofecoxib Reduce Regional Cerebral Blood Flow Evoked by Somatosensory Stimulation in Rats

2002 ◽  
Vol 227 (7) ◽  
pp. 465-473 ◽  
Author(s):  
Rumiana Bakalova ◽  
Tetsuia Matsuura ◽  
Iwao Kanno
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Drug Application ◽  
Cyclooxygenase Inhibitors ◽  
Regional Cerebral Blood ◽  
Somatosensory Stimulation ◽  
Doppler Flowmetry ◽  
Cox Inhibitor ◽  
Cox 2

The present study was designed to investigate whether administration of indomethacin (IMC), a non-selective cyclooxygenase (COX-1 and COX-2) inhibitor, and Rofecoxib, a highly selective COX-2 inhibitor, affect the regulation of regional cerebral blood flow response evoked by somatosensory activation (evoked rCBF). IMC and Rofecoxib were applied intravenously (6.25 and 3 mg/kg/hr, respectively). Somatosensory activation was induced by electrical hind paw stimuli of 0.2, 1, and 5 Hz (5-sec duration, 1.5 mA). The evoked rCBF was measured in α-chloralose anesthetized rats using laser-Doppler flowmetry. Before and after drug application, the evoked rCBF showed a frequency-dependent increase in the range of 0.2–5 Hz stimulation. IMC reduced significantly (about 50%–60%) evoked rCBF in response to all frequencies of hind paw stimulation (P< 0.05). Rofecoxib reduced significantly (about 50%) evoked rCBF in response to 1 and 5 Hz stimulation (P < 0.05), but did not affect evoked rCBF at 0.2 Hz. After IMC or Rofecoxib application, the normalized evoked rCBF curves peaked earlier as compared with that before their application (P < 0.05), although the rise time of 0.5 sec was nearly constant regardless of the stimulus frequency. The termination time of evoked rCBF curves was changed significantly after IMC application at 0.2 Hz stimulation (P < 0.05), but was not affected after Rofecoxib application. Neither COX inhibitor significantly affected the baseline level of CBF. The results suggest a participation of COX products in the regulation of evoked rCBF in response to somatosensory stimulation in the brain.

Regional cerebral blood flow response to vibrissal stimulation in mice lacking type I NOS gene expression

1996 ◽  
Vol 270 (3) ◽  
pp. H1085-H1090 ◽  
Author(s):  
J. Ma ◽  
C. Ayata ◽  
P. L. Huang ◽  
M. C. Fishman ◽  
M. A. Moskowitz
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
No Production ◽  
Type I ◽  
Regional Cerebral Blood ◽  
Doppler Flowmetry ◽  
Cranial Window ◽  
Whisker Stimulation ◽  
Neuronal Nos

The role of nitric oxide (NO) in cerebral blood flow-metabolism coupling was assessed in SV-129 wild-type (WT) and neuronal (type I) NO synthase (NOS) knockout mice (Kn). Regional cerebral blood flow (rCBF; laser-Doppler flowmetry) was measured over the contralateral cortical barrel field during unilateral mechanical vibrissal deflection (2-3 Hz, 60 s) under urethan anesthesia. The rCBF response was similar in WT and Kn and did not differ when recorded over the intact skull or closed cranial window preparations. Whisker stimulation increased rCBF by 41 +/- 8% (maximum) and 27 +/- 6% (mean) in WT (n = 6) and 41 +/- 7% (maximum) and 26 +/- 6% (mean) in Kn (n = 6) when recorded through a closed cranial window. After superfusion with topical N omega-nitro-L-arginine (L-NNA; 1 mM), the rCBF response was inhibited by approximately 45% in WT mice (P < 0.05), whereas there was no inhibition in Kn. Endothelium-dependent relaxation, assessed by pial vessel dilation in response to topical acetylcholine (100 microM) and inhibition by L-NNA (1 mM), was the same in both groups. Our results suggest that 1) endothelial NO production does not mediate the rCBF coupling to neuronal activity in Kn, 2) the inhibitory effect of L-NNA on the rCBF response to whisker stimulation in WT is a consequence of type I (neuronal) NOS inhibition, and 3) NO-independent mechanisms couple rCBF and metabolism during whisker stimulation in mice lacking expression of neuronal NOS.

scholarly journals l-Arginine-Induced Regional Cerebral Blood Flow Increase is Abolished after Transient Focal Cerebral Ischemia in the Rat

1997 ◽  
Vol 17 (10) ◽  
pp. 1074-1080 ◽  
Author(s):  
Bernd Sporer ◽  
K. Helge Martens ◽  
Uwe Koedel ◽  
Roman L. Haberl
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Cerebral Ischemia ◽  
Regional Cerebral Blood Flow ◽  
Focal Cerebral Ischemia ◽  
Regional Cerebral Blood ◽  
Doppler Flowmetry ◽  
Transient Focal Cerebral Ischemia ◽  
Reperfusion Period ◽  
Synthase Inhibitor

We investigated the l-arginine-induced, regional cerebral blood flow (rCBF) enhancement after different durations of transient focal cerebral ischemia in the rat to determine if l-arginine increases rCBF after transient focal cerebral ischemia. Focal ischemia (5 minutes and 20 minutes) followed by 90 minutes of reperfusion was induced in a normotensive rat suture-model. Regional cerebral blood flow in both hemispheres was measured by laser-Doppler-flowmetry. Reactivity of rCBF to l-arginine (300 mg/kg) was measured 45 minutes after reperfusion, and hypercapnia 90 minutes after reperfusion. The effect of d-arginine and pretreatment with the nitric oxide (NO) synthase inhibitor Nω-nitro-l-arginine (l-NA) (10 mg/kg) was examined in additional groups. Hypercapnia and l-arginine increased rCBF in sham operated controls and on the nonischemic hemispheres. d-arginine did not. Twenty-minute long ischemia significantly reduced the response to l-arginine (control side: 115 ± 5.9%; ischemic side: 107 ± 6.1%, n = 7) and hypercapnia, 5 minutes of ischemia did not. Nω-nitro-l-arginine pretreatment partly restored the l-arginine-induced rCBF increase. Thus, rCBF increase caused by l-arginine in the reperfusion period was unaffected by 5 minutes of ischemia, but reduced by 20 minutes of ischemia. The restoration after pretreatment with l-NA may be caused by attenuated production of cytotoxic substances, e.g., NO and related compounds.

scholarly journals Tyrosine Kinase Inhibition Reduces Inflammation in the Acute Stage of Experimental Pneumococcal Meningitis

2004 ◽  
Vol 72 (6) ◽  
pp. 3294-3298 ◽  
Author(s):  
Klemens Angstwurm ◽  
Uwe-Karsten Hanisch ◽  
Tarraneh Gassemi ◽  
Margrethe Bastholm Bille ◽  
Marco Prinz ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Intracranial Pressure ◽  
Bacterial Meningitis ◽  
Tyrosine Kinase ◽  
Cell Walls ◽  
Regional Cerebral Blood Flow ◽  
Host Immune System ◽  
Regional Cerebral Blood ◽  
Tnf Α

ABSTRACT Bacterial meningitis is an acute inflammatory disease of the central nervous system with a mortality rate of up to 30%. Excessive stimulation of the host immune system by bacterial surface components contributes to this devastating outcome. In vitro studies have shown that protein tyrosine kinase inhibitors are highly effective in preventing the release of proinflammatory cytokines induced by pneumococcal cell walls in microglia. In a well-established rat model, intracisternal injection of purified pneumococcal cell walls induced meningitis characterized by increases in the regional cerebral blood flow and intracranial pressure, an influx of leukocytes, and high concentrations of tumor necrosis factor alpha (TNF-α) in the cerebrospinal fluid. Compared with the values at the beginning of the experiment, intraperitoneal injection of tyrphostin AG 126 reduced the increases in regional cerebral blood flow (at 6 h, 127% ± 14% versus 222% ± 51% of the baseline value; P < 0.05) and intracranial pressure (at 6 h, 0.8 ± 2.4 versus 5.4 ± 2.0 mm of Hg; P < 0.05), the influx of leukocytes (at 6 h, 1,336 ± 737 versus 4,350 ± 2,182 leukocytes/μl; P < 0.05), and the TNF-α concentration (at 6 h, 261 ± 188 versus 873 ± 135 pg/μl; P < 0.05). These results demonstrate that inhibition of AG 126-sensitive tyrosine kinase pathways may provide new approaches for preventing excessive inflammation and reducing the increases in blood flow and intracranial pressure in the acute phase of bacterial meningitis.

The Characteristics of Laser-Doppler Flowmetry for the Measurement of Regional Cerebral Blood Flow

Neurosurgery ◽  
1995 ◽  
Vol 36 (2) ◽  
pp. 358-364 ◽  
Author(s):  
Osamu Fukuda ◽  
Shunro Endo ◽  
Naoya Kuwayama ◽  
Jun Harada ◽  
Akira Takaku
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Laser Doppler Flowmetry ◽  
Regional Cerebral Blood Flow ◽  
Laser Doppler ◽  
Regional Cerebral Blood ◽  
Doppler Flowmetry
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